The red-billed scythebill (Campylorhamphus trochilirostris) is a species of bird in the subfamily Dendrocolaptinae of the ovenbird family Furnariidae.

It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Panama, Paraguay, Peru, and Venezuela.

Adults of the nominate subspecies C. t. trochilirostris have a thinly streaked face and neck with a weak supercilium.

Their underparts are a slightly lighter brown than the back; their breast has buff streaks that narrow on the belly but don't continue onto the undertail coverts.

In the Amazon Basin it favors seasonally flooded várzea and igapó forest and riverside canebrakes.

[4] The red-billed scythebill's diet is chiefly arthropods, especially soft-bodied ones like spiders, and also includes small vertebrates.

It typically takes its prey by probing crevices and holes in bark, bamboo, rotting wood, moss clumps, bromeliads, and epiphytes.

In western Ecuador and Peru it is "a descending and gradually slowing series of fewer whistled notes, 'tuwee-tuwee-toowa-tew-tew' ".

[4] In northeastern Brazil the song is "a short series of fluted notes 'wuut wuut wit-wit-triffit' " that ascends at the end.